We propose to determine if the nitroxyl free radical of the carcinogen N-hydroxy-2-acetyl aminofluorene (N-OH-AFF) generated by flash photolysis will react directly with nucleic acids. We have discovered a new reaction in which 2-nitrosofluorene adds to double bonds of lipids in the membrane. We propose to determine the reduction-oxidation properties of this new adduct. In addition, we propose to determine if there is a perioxidase(s) in mammary gland parenchymal which will activate N-OH-AAF via the free radical intermediate route. We also propose to use spin traps in an attempt to determine if primary free radicals are responsible for the oxidation of N-OH-AAF in the free activation route. BIBLIOGRAPHIC REFERENCES: Floyd, R.A. and Soong, L.M. (1977) Spin Trapping in Biological Systems Oxidation of the Spin Trap 5,5-Dimethyl-1-Pyrroline-1-Oxide by a Hydroperoxide-Hematin System, Biochem. Biophys. Res. Commun. 74: 79-84. Floyd, R.A. (1977) Free Radicals Produced in the Reaction of the Carcinogen 2-Nitrosofluorene with Unsaturated Lipids, Experientia 33: 197-198.